Il A heavy ball with a weicht of 100 N (m 10.2 kg) is hung. from the ceiling of a lecture hall on a 4.5-m-long rope. The ball. is pulled to one side and released to swing as a pendulum, reach-. ing a speed of 5.5 m/s as it passes throuoh the lowest point.
Inventions. The huochong gun was invented in China during the Ming dynasty. It was also called the tongjiangjun, which meant bronze general. This was an important invention of the time period because the Ming Dynasty was creating weapons to defend their dynasty, and they came across the gun.t was also called the tongjiangjun, which meant bronze general. This was an important invention of the time period because the Ming Dynasty was creating weapons to defend their dynasty, and they came across the gun.
The Ming dynasty, which succeeded the Yuan (Mongol) dynasty (1206â1368), was founded by Zhu Yuanzhang. Zhu, who was of humble origins, later assumed the reign title of Hongwu. The Ming became one of the most stable but also one of the most autocratic of all Chinese dynasties.